CodeBreaker2018 walkthrough, Task 2 Secrets

Let’s look at Task 2 before doing Task 1. It is a much quicker and easier task, and it is a good warm-up practice in reverse engineering before we dive into the much more complicated Task 1.

In this task we are asked to extract a secret key from the binaries left over by the ransomware. To solve this we need to use some reverse engineering tools.

The organizers of recommend IDAPro or Binary Ninja. IDAPro is indeed an excellent tool, but unfortunately in order to get the full functionality you have to buy the complete version which is quite pricey. I have never used the Binary Ninja, looks like a good tool, but also expensive.

The first one is a web application, you don’t need anything to install. The second one is an open source tool which is a package with many distributions. For example, on Mac you can use the excellent Homebrew package manager to install it.

brew install radare2

Radare will come in handy for Task 1. In this task we’ll stick with Dissasembler.io.